Heat flows naturally through the TEG because its cold side is kept at room temperature, while its hot side, which is in thermal contact with the cell, is at a high temperature. The Seebeck effect, which is the direct conversion of temperature differences between two semiconductor materials into electric voltage, generates this difference which then translates into additional electrical power.

The scientists decided not to use a spectrum splitting technology, which is generally utilized in these applications, to direct different parts of the solar spectrum towards either the PV or the TEG unit. “It is more convenient, in terms of final efficiency gains, to keep the solar cell at the same temperature of the TEG hot side, instead of keeping the cell cold but losing much of the recoverable heat,” the academics explained, noting that a wide-gap solar cell based on perovskite was chosen for the device, due to its lower sensitivity to high temperatures. “Temperature-sensitive materials, such as silicon, lose too much efficiency to make the hybridization convenient,” they further explained.

German researchers developed a lattice arrangement of three different layers of ferroelectric crystals that created a powerful photovoltaic effect.

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Combining ultra-thin layers of different materials can raise the photovoltaic effect of solar cells by a factor of 1,000 according to researchers at Martin Luther University Halle-Wittenberg (MLU) in Germany.

Their findings, published in the journal “Science Advances,” described a lattice arrangement of three different layers of ferroelectric crystals (in this case, of barium titanate, strontium titanate, and calcium titanate) that created a powerful solar energy producing effect.

Ferroelectric means that the material has spatially separated positive and negative charges. The charge separation leads to an asymmetric structure that enables electricity to be generated from light.